Learning to SCUBA dive at an early age in the chilly Gulf of Maine gave me exciting views of an incredible hidden world. This led to other adventures exploring the salty world beneath the waves, researching whales, coral reefs and fisheries. On one of these occasions I spent about six months on a tall ship, where our drinking water was taken from the ocean and filtered by a specialized, high pressure, reverse osmosis (RO) membrane. The RO takes in sea water and rejects the salts, leaving fairly pure, fresh water. People can’t drink sea water directly because it puts the body’s natural balance of salts out of whack—there’s so much salt in sea water that it actually drives the water out of our bodies. Not so good when you’re thirsty. I’m reminded of a line from an old poem, the Rime of the Ancient Mariner, where a sailor and his boat were trapped far from land: “Water, water every where Nor any drop to drink.”

It’s incredible that the oceans hold over 97% of all the water on our planet. The remaining is fresh water, most of which is locked up in the polar ice caps and permanent ice on mountains; less than 1% of the Earth’s water is potentially available for drinking. If you filled a five gallon bucket and said that it represents all the water on our planet, nearly all of it would be too salty to drink. In fact, roughly ½ a cup from that whole bucket would represent all that we have in the ground, our lakes, rivers, and ponds. Consider that even less than that is easy to make safe for drinking—not so muddy, brackish or polluted that extra measures are needed. Unfortunately, there are many places where people can’t afford to treat the water and end up drinking it as-is, contaminants and all. The worse the water quality is, the harder we have to work to make our tiny existing fresh water supplies drinkable.

This means, for those who can afford treatment, we put in energy, equipment, disinfection chemicals, time and effort to make it potable. Is all that water in our oceans unavailable to us, like it was for the Ancient Mariner? Like on my ship, when it comes to salts, high pressure RO membranes are now used for many communities around the world (including here in the United States) to make drinkable water from the oceans. Another common way to do this is distillation. These are important technologies for areas with access to salty water but not enough fresh and as you may have guessed they do require significant energy inputs. 

Image courtesy of DewPoint Systems.

Another interesting technology, DewPoint Systems' RainDome,uses naturally cool sea water to draw moisture from the air without electricity or moving parts. In coastal areas where the conditions are right, the fresh water it makes can be used for drinking and even to irrigate crops.Using the oceans to produce drinking water is not only possible, increasingly, it’s a reality for a thirsty world.
 

Want to learn more? Check out the following resources.

Desalination by Reverse Osmosis:

• Reverse Osmosis on How Stuff Works
  
• Desalination by Reverse Osmosis in the UNEP Source Book

Contact Mark B.

We use water in so many ways, just around the house. For most of us, it’s always there – just turn the faucet handle and get instant gratification along with the wet stuff. Lose that water from a power outage or a break in the water main and we very quickly remember how incredibly important it is. My own appreciation list is a long one – I use it to: drink for health and hydration, provide to pets and houseplants, wash dishes, fruit and veggies, my body, clothes, and the car, flush the toilet, and to brush teeth. What’s on your list? In these days of increasing water scarcity, it pays to ensure the supply of clean waters lasts as long as it can. It’s not free, and making water clean enough to use costs extra - conservation helps the wallet now and leaves more for the future.

One way to cut back is to replace older appliances with ones that limit the amount of water that gets used each time. Last year when our washing machine finally broke beyond my ability to fix it yet again, I replaced it with a high efficiency front loader. As much as I hate putting things into the landfill before their time, I really might have thought to do this earlier: not only is the electrical cost cut to less than half, it uses about one third the water without sacrificing how clean the clothes get. I pay a lot for my water (and electricity), so that’s a pretty sweet deal.

One study found American homes have around 11 toilet flushes per day (Rockaway et at, 2011). Where the older toilets may use 3.5 gallons per flush (gpf), a water conserving toilet uses just 1.6 gpf, saving about 7,600 gallons a year in that household. That’s a lot of water! I replaced the toilets when we moved into our house not too long ago, but I hadn’t realized until just now how much this has impacted our water usage and the utility bills.

A few other useful things we can do include:

• Install low flow shower heads and faucets. These don’t reduce the pressure of the water coming out so it should still feel like it’s at full force, but the volume is limited.

• Consider watering the lawn only when needed instead of using a timer. Those with irrigation systems can save water by using a sensor to control when it turns on based on the weather or how dry the soil actually is. • Use a soaker hose or drip emitters to water just the outdoor plants you want to target.

• If you feel you have to use chemicals on the lawn or farm, follow the directions scrupulously to reduce how much ends up in the environment or even back in your drinking water. That should help keep down the cost of treating your water to make it safe to drink. And when pollutants are removed, a fair amount of water can be used to carry them away, so less contamination can means less wasted water too.

How do you use water? For just a day, try to be conscious of each time you open a faucet, do a load of laundry, or flush the toilet. What would it be like to do without? There are some fairly easy ways to reduce, saving both water and money. The more we save today, the more there is tomorrow.

Contact Mark B.

In May, 2012, I returned to Nicaragua with Aqua Clara International and Fairmount Minerals. We worked with the slow sand filters that Aqua Clara and a group called AMOS have been installing throughout the country. Access to safe drinking water is a major health issue Nicaragua and in many other places around the world. Slow sand filtration is not new, nor is it unique to Aqua Clara or Nicaragua. The ones I’m talking about provide drinking water to a single household but they can also be bigger to serve a school or community. Household filters come in different shapes and sizes, depending on whose design it is and what materials are available. Basically, it is a container with a layer of coarse gravel at the bottom with smaller and small gravel on top of that, until finally the topmost layer is fine sand. Dirty water is poured in at the top and displaces filtered water so the good stuff just pours out the tap. The sand does more than simply strain out the bad stuff – it supports a biological environment that gives the harmless microbes the opportunity to eat or out-compete the ones that make people sick. It’s a simple but highly effective technology for the prevention of water-borne diseases.

Household slow sand filters are normally made by local people with locally available materials, which serve an overarching goal of helping people to help themselves. When parts and materials are not specially imported, a drinking water filter becomes more financially accessible to the end user and more serviceable. Another important benefit of this strategy is that the builders develop an intimate understanding of how these things are supposed to work – this enables them to also teach about and repair the units.

One of the interviews we had in May included a family that had been using the slow-sand filter for about six months. The father reported that he can now work every day because he no longer feels weak, and specific health issues were better than they had been in years. He felt this was because he was now drinking the filtered water. That made sense considering the consequences for an adult body to be constantly fighting off infections in the gut.

Simply put, slow sand filters can and do change and save lives every day. If you’re interested in exploring further, here are just a few links to some of the many resources available on the subject.

• World Health Organization, Water Sanitation and Health, "Slow Sand Filtration"
• Surfers Without Borders, "Slow Sand Filtration"
• National Environment Service Center, National Drinking Water Clearinghouse, "Slow Sand Filtration"
• Biosand Filter
• Centre for Affordable Water and Sanitation Technology (multiple resources on Biosand Filters)

An additional list of resources for slow sand filters can be found here.

Contact Mark B.

Aqua Clara provides point-of-use water filters to impoverished people in developing countries. Kinetico hosted an information session where employees from Kinetico and Fairmount Minerals learned how these slow-sand water filters are made and about the programs that train people in rural communities how to make and maintain them. 

Nicaragua is the second poorest nation in the western hemisphere: the average income is about three dollars a day. There are major health problems, especially in rural areas, caused by drinking contaminated water. As a result, people have to spend money on medicines to treat water-borne diseases. Because they are sick so often, they have less time for work or going to school. This reinforces a cycle of poverty and disease that can be difficult to break without outside resources.

The Aqua Clara program includes educating the end-users on why the slow-sand filters are important and how to build, use and maintain them. A key part of program success is regular follow-up visits for additional support. In November 2011, I went to Nicaragua to be part of a team that included folks from Fairmount Minerals, Aqua Clara and Nicaraguans. We went to remote villages to see whether existing slow-sand filters were being used properly and to find out how effective they actually were. Deep in the tropical volcanic hills, we were greeted by village leaders and taken to homes where filters had been installed. The water filters were frequently located in a hot, dark kitchen that was sometimes just 6’ x 7’, had a swept dirt floor, a tin roof, and walls made from whatever was available. Often chickens and other animals were present. 

The filters we examined ranged from months to years old. Our assessments included household interviews mostly with the matriarchs. In many places, it is not unusual for women and older girls to be responsible for making sure the home has enough water for their cooking and cleaning as well as for the family to drink. In many African villages this can mean a child has to walk for miles to bring the water back home, though where we were in Nicaragua water was drawn from nearby wells. Our site visits also included measuring turbidity and taking water samples from the raw source and the filter outlet so we could grow bacteria on special plates and find out just how bad the situation was.

As you can see from the photo, these filters dramatically reduced the amount of bacteria in the water. The blue spots are actually colonies of dangerous E. coli, and the red spots are coliform bacteria.

Once the bacteria plates had time to incubate and I saw the results, I took a moment to look around again. What I saw were toddlers exploring and children laughing, playing and going to school. I saw families who depend on being healthy enough to make whatever living they could from small plots of land way out in the hinterlands. As a former Peace Corps Volunteer, it not only brought back memories, but also reinforced why this kind of work continues to be so important. Health in rural communities like the ones we were in starts with clean water. It’s good to be part of a company that intimately knows the value of water and is committed to sharing our knowledge to help others gain access to safe and adequate supplies.

Photos courtesy of Dave Chew.

Contact Mark B.